A nozzle flow control bypass with a pressure stabilizing chamber

Abstract

This invention discloses a flow control bypass for a nozzle with a pressure-stabilizing chamber, comprising a bypass inlet, a bypass outlet, and a pressure-stabilizing chamber sequentially distributed upstream to downstream along the airflow direction within the nozzle. The internal flow channel of the nozzle includes a nozzle inlet, a straight section of the internal flow channel, a converging section of the internal flow channel, a nozzle throat, an expanding section of the internal flow channel, and a nozzle outlet, sequentially distributed along the airflow direction. The bypass inlet is upstream connected to the straight section of the internal flow channel and downstream connected to the pressure-stabilizing chamber. The bypass outlet is upstream connected to the pressure-stabilizing chamber and downstream connected to the nozzle throat and / or the expanding section of the internal flow channel. The pressure-stabilizing chamber receives the airflow from the bypass inlet, rectifys it within the chamber, and then exits through the bypass outlet. This invention reduces the weight of the flow control bypass wall while simultaneously achieving airflow rectification within the pressure-stabilizing chamber, resulting in better uniformity and less airflow pulsation in the airflow exiting the pressure-stabilizing chamber.

Description

Technical Field

[0001] This invention belongs to the field of advanced aero-engine exhaust system design, and specifically relates to a nozzle flow control bypass. Background Technology

[0002] With the development of science and technology and the urgent needs in practical applications, ducting air and controlling flow have become common and effective measures in the field of advanced aviation to improve performance.

[0003] To achieve the above objectives, establishing an air intake path through pipes fixed to a defined wall surface has become an important measure. However, pipes with fixed wall surfaces significantly affect the spatial layout of the equipment, increase weight, and common rigid pipes are difficult to apply to adjustable mechanisms, resulting in mutual constraints.

[0004] In the case of aero-engine nozzles, the aforementioned bleed air ducts are extremely common and are often referred to as flow control bypasses. Common Laval nozzles can use flow control bypasses to control flow separation at the nozzle's expansion section wall. Adaptive bypass dual-throat aerodynamic thrust vectoring nozzles can adjust the nozzle's thrust vector angle by controlling the bypass opening. Many similar applications exist. Most of these bypasses are fixed geometry, non-adjustable, and rigid, thus often suitable for nozzles with fixed geometry. When used in adjustable nozzles, a trade-off must be made between the rigid bypass and the adjustable nozzle itself, often resulting in increased weight, increased complexity, reduced component reliability, and decreased aerodynamic performance.

[0005] Therefore, designing a flow control bypass that is flexible, lightweight, and high-performance is a key factor affecting whether nozzle flow control can function effectively. Summary of the Invention

[0006] The purpose of this invention is to provide a nozzle flow control bypass with a pressure stabilizing chamber, so as to reduce the weight of the flow control bypass wall, while realizing the rectification of the airflow in the pressure stabilizing chamber, resulting in better uniformity of the airflow flowing out of the pressure stabilizing chamber and less airflow pulsation.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A flow control bypass for a nozzle with a pressure stabilizing chamber includes a bypass inlet, a bypass outlet, and a pressure stabilizing chamber sequentially distributed upstream to downstream along the airflow direction within the nozzle. The internal flow channel of the nozzle includes a nozzle inlet, a straight section of the internal flow channel, a converging section of the internal flow channel, a nozzle throat, an expanding section of the internal flow channel, and a nozzle outlet sequentially distributed along the airflow direction. The bypass inlet is connected upstream to the straight section of the internal flow channel and downstream to the pressure stabilizing chamber. The bypass outlet is connected upstream to the pressure stabilizing chamber and downstream to the nozzle throat and / or the expanding section of the internal flow channel. The pressure stabilizing chamber receives the airflow from the bypass inlet, rectifys it within the chamber, and then exits through the bypass outlet.

[0009] The number of bypass entrances and bypass exits is independently one or more.

[0010] The pipe downstream of the bypass inlet extends into the pressure stabilizing chamber, and the length of the extended portion of the pipe inside the pressure stabilizing chamber is 5%-10% of the length of the pipe outside the pressure stabilizing chamber where the bypass inlet is located.

[0011] The pipeline upstream of the bypass outlet extends into the pressure stabilizing chamber, and the length of the extended portion of the pipeline inside the pressure stabilizing chamber is not less than 20% of the length of the pipeline outside the pressure stabilizing chamber where the bypass inlet is located.

[0012] The pipe inlet upstream of the bypass outlet is equipped with a flared opening.

[0013] The shape of the voltage stabilizing chamber is variable.

[0014] The boundary of the pressure stabilizing chamber is the outer wall surface, inner wall surface, or internal partition plate of the nozzle, or the geometric boundary of other parts. The boundary of the pressure stabilizing chamber is rigid or flexible, and no gas permeates or leaks from the boundary of the pressure stabilizing chamber.

[0015] The internal volume of the pressure stabilizing chamber is more than three times the internal volume of the bypass pipe that was replaced.

[0016] Beneficial effects: The nozzle flow control bypass with a pressure stabilizing chamber provided by this invention has the following advantages compared with the prior art:

[0017] (1) A generalized concept of pressure stabilizing cavity is defined, eliminating the concept of fixed wall and fixed flow channel of traditional airflow bypass, reducing the solid wall required for airflow bypass, and the weight of a single flow control bypass is expected to be reduced by more than 50%.

[0018] (2) The rectification of the airflow in the pressure stabilizing chamber makes the airflow out of the pressure stabilizing chamber more uniform and the airflow pulsation smaller, which helps to achieve more efficient flow control; it can be applied to the flow control of the vector generation of the aerodynamic thrust vector nozzle, which is expected to increase the thrust vector angle by more than 20%.

[0019] (3) By adding a pressure stabilizing chamber to the flow control bypass, the geometric, spatial and motion constraints of the flow control bypass caused by the fixed wall and fixed geometry are reduced, making it more suitable for flow control bypass in adjustable nozzles.

[0020] (4) The structure is simple, greatly simplifying the complex surface caused by the flow control bypass. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a nozzle flow control bypass with a pressure stabilizing chamber according to the present invention;

[0022] Figure 2 A schematic diagram of a flow control bypass with a pressure stabilizing chamber for a Laval nozzle;

[0023] Figure 3 A schematic diagram of a flow control bypass design with a pressure stabilizing chamber for a bypass-type dual-throat nozzle;

[0024] Figure 4 This is a simplified schematic diagram of a nozzle flow control bypass with a pressure stabilizing chamber.

[0025] Figure 5 This is a schematic diagram of a nozzle flow control bypass design with a pressure stabilizing chamber, a bypass inlet, and multiple bypass outlets.

[0026] Figure 6 Mach number cloud map for typical operating conditions of traditional bypass dual-throat nozzles;

[0027] Figure 7 Mach number contour plot for typical operating conditions of a bypass-type dual-throat nozzle with a pressure-stabilizing chamber flow control bypass.

[0028] In the diagram: 1. Nozzle inlet, 2. Straight section of the nozzle inner flow channel, 3. Bypass inlet, 4. Pressure stabilizing chamber, 5. Converging section of the nozzle inner flow channel, 6. Nozzle throat, 7. Bypass outlet, 8. Expanding section of the nozzle inner flow channel, 9. Outer wall of the nozzle, 10. Nozzle outlet. Detailed Implementation

[0029] The present invention will be further explained below with reference to the accompanying drawings.

[0030] like Figures 1 to 4 As shown, the present invention provides a flow control bypass for a nozzle with a pressure stabilizing chamber, which is disposed in the nozzle. The internal flow channel of the nozzle involved includes a nozzle inlet 1, a straight section 2 of the internal flow channel 2, a converging section 5 of the internal flow channel 5, a nozzle throat 5, an expanding section 8 of the internal flow channel 8, and a nozzle outlet 10, which are distributed sequentially along the airflow direction.

[0031] The present invention provides a flow control bypass for a nozzle with a pressure stabilizing chamber, comprising a bypass inlet 3, a bypass outlet 7, and a pressure stabilizing chamber 4, which are sequentially distributed upstream to downstream along the airflow direction within the nozzle.

[0032] The bypass inlet 3 is connected upstream to the straight section 2 of the nozzle inner flow channel, and downstream to the pressure stabilizing chamber 4.

[0033] The bypass outlet 7 is connected upstream to the pressure stabilizing chamber 4 and downstream to the nozzle throat 5 or the nozzle inner flow channel expansion section 8, or multiple bypass outlets 7 are connected to the nozzle throat 5 and the nozzle inner flow channel expansion section 8 respectively.

[0034] The pressure stabilizing chamber 4 is used to receive the airflow from the bypass inlet 3 and rectify it in the pressure stabilizing chamber 4 before it flows out through the bypass outlet 7.

[0035] The flow control bypass with a pressure-stabilizing chamber of this invention adopts a structure of bypass inlet, pressure-stabilizing chamber, and bypass outlet, replacing the original bypass inlet, bypass pipe, and bypass outlet structure; that is, the pressure-stabilizing chamber replaces the original bypass pipe. The pressure-stabilizing chamber is characterized by being a sealed space except for the bypass inlet and bypass outlet, and has a large, variable internal volume. The pressure-stabilizing chamber has a variable shape and a defined number of airflow inlets and outlets, reducing the weight of the flow control bypass walls, while simultaneously achieving airflow rectification within the pressure-stabilizing chamber, resulting in better airflow uniformity and less airflow pulsation when exiting the pressure-stabilizing chamber.

[0036] The boundary of the pressure stabilizing chamber 4 is the outer wall, inner wall, or internal partition plate of the nozzle, made of rigid or flexible material, with no gas permeating or leaking from the boundary of the pressure stabilizing chamber. This reduces the geometric, spatial, and kinematic constraints of the flow control bypass caused by fixed walls and fixed geometry, making it more suitable for flow control bypasses in adjustable nozzles.

[0037] Compared to the replaced bypass pipe, the internal volume of the pressure stabilizing chamber is significantly larger; generally, the internal volume of the pressure stabilizing chamber is more than three times that of the replaced bypass pipe; this improves the uniformity of the secondary flow out of the nozzle bypass outlet and reduces airflow pulsation.

[0038] The number of bypass inlets and bypass outlets can be one or more independently. Generally, a one-bypass-inlet-one-bypass-outlet configuration is commonly used for flow control in simple nozzle internal flow channels, such as secondary flow control to improve flow separation in large expansion ratio Laval nozzles, and secondary flow control in aerodynamic thrust vectoring nozzles for vector generation and regulation. A one-bypass-inlet-multiple-bypass-outlets configuration is commonly used in various application scenarios, such as nozzle wall cooling, and secondary flow control in aerodynamic thrust vectoring nozzles for vector generation and regulation.

[0039] The pipeline downstream of bypass inlet 3 extends into pressure stabilizing chamber 4, and the length of the extension within pressure stabilizing chamber 4 is 5%-10% of the length of the pipeline outside pressure stabilizing chamber 4 at bypass inlet 3. The pipeline upstream of bypass outlet 7 extends into pressure stabilizing chamber 4, and the length of the extension within pressure stabilizing chamber 4 is not less than 20% of the length of the pipeline outside pressure stabilizing chamber 4 at bypass inlet 3.

[0040] The duct downstream of the bypass inlet can be completely identical to the original bypass duct. The duct inlet upstream of bypass outlet 7 is equipped with a bell mouth to rectify the airflow.

[0041] The present invention can be better understood from the following embodiments.

[0042] Example 1

[0043] Figure 4 This diagram illustrates a simplified flow control bypass design for a nozzle with a pressure-stabilizing chamber. All black solid lines in the diagram represent solid nozzle walls of a certain thickness. The pressure-stabilizing chamber has a configuration of one bypass inlet and one bypass outlet. The cavities inside the nozzle throat convergent section and the nozzle diverging section together constitute the pressure-stabilizing chamber.

[0044] Example 2

[0045] Figure 5 This is a schematic diagram of a nozzle flow control bypass design with a pressure stabilizing chamber, one bypass inlet, and multiple bypass outlets. It has one bypass inlet and a total of six bypass outlets (three on each side). One set is used for flow control throat, and the other two sets are used for cooling nozzle walls.

[0046] Example 3

[0047] Figure 7 A flow control bypass design for nozzles with a pressure stabilizing chamber is demonstrated. This solution is designed for bypass-type dual-throat nozzles, reducing the original... Figure 6 The adaptive bypass channel in the middle is changed to, for example Figure 7 An adaptive bypass with a pressure-stabilizing chamber. Under the same nozzle operating pressure ratio NPR = 4, the improved dual-throat aerodynamic thrust vectoring nozzle with adaptive bypass and pressure-stabilizing chamber of this invention outperforms the benchmark dual-throat aerodynamic thrust vectoring nozzle ( Figure 6 The thrust vector angle increased from the baseline 15.93° to 20.64°, an increase of 29.6%; the thrust coefficient increased from the baseline 0.947 to 0.964, an increase of 1.2%, demonstrating the technical advantages of the present invention.

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A nozzle flow control bypass with a pressure stabilizing chamber, characterized in that: The nozzle includes a bypass inlet (3), a bypass outlet (7), and a pressure stabilizing chamber (4) distributed sequentially from upstream to downstream along the airflow direction within the nozzle; the internal flow channel of the nozzle includes a nozzle inlet (1), a straight section (2), a converging section (5), a throat (5), an expanding section (8), and an outlet (10) distributed sequentially along the airflow direction; the bypass inlet (3) is connected upstream to the straight section (2) and downstream to the pressure stabilizing chamber (4); the bypass outlet (7) is connected upstream to the pressure stabilizing chamber (4) and downstream to the throat (5) and / or the expanding section (8); the pressure stabilizing chamber (4) is used to receive the airflow from the bypass inlet (3) and rectify it in the pressure stabilizing chamber (4), and then flow out through the bypass outlet (7); The pipeline downstream of the bypass inlet (3) extends into the pressure stabilizing chamber (4), and the length of the extended portion of the pipeline downstream of the bypass inlet (3) in the pressure stabilizing chamber (4) is 5%-10% of the length of the pipeline outside the pressure stabilizing chamber (4) of the bypass inlet (3); The pipe upstream of the bypass outlet (7) extends into the pressure stabilizing chamber (4), and the length of the extended portion of the pipe upstream of the bypass outlet (7) in the pressure stabilizing chamber (4) is not less than 20% of the length of the pipe outside the pressure stabilizing chamber (4) of the bypass inlet (3); The pipe inlet upstream of the bypass outlet (7) is provided with a bell mouth; The shape of the pressure stabilizing cavity (4) is variable.

2. The nozzle flow control bypass with a pressure stabilizing chamber according to claim 1, characterized in that: The number of bypass entrances and bypass exits is independently one or more.

3. The nozzle flow control bypass with a pressure stabilizing chamber according to claim 1, characterized in that: The boundary of the pressure stabilizing chamber (4) is the outer wall surface, inner wall surface, or internal partition plate of the nozzle, or the geometric boundary of other parts. The boundary of the pressure stabilizing chamber (4) is rigid or flexible, and no gas permeates or leaks from the boundary of the pressure stabilizing chamber.

4. The nozzle flow control bypass with a pressure stabilizing chamber according to claim 1, characterized in that: The internal volume of the pressure stabilizing chamber (4) is more than three times the internal volume of the bypass pipe that was replaced.

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